Technological Field
The described technology generally relates to a multifunction probe of primary references for aircraft.
Description of the Related Technology
In aeronautics, the piloting of an aircraft is based on knowledge of the primary references thereof. These references comprise, inter alfa, its speed relative to the ambient air, the temperature, its altitude and its angle of attack.
These references are determined via probes situated on the cockpit of the aircraft. In a known manner, these probes may comprise pitot tubes and static pressure probes for measuring the total and static pressure, respectively, as well as angle of attack probes and laser anemometer probes, called Light Detection and Ranging (LIDAR) probes, which send and receive laser radiation along one or more axes.
These probes are then connected to a capability for measuring and computing corresponding primary references of the aircraft, such as its altitude, angle of attack, relative airspeed, etc.
The measurements are next grouped together and displayed on a screen of the Electronic Flight Instrument System (EFIS), which is a central information source from which the aircraft is piloted.
In a known manner, the angle of attack probes and pitot tubes assume the form of pallets and tubes protruding from the skin of the aircraft.
As a result, they are exposed to meteorological or mechanical factors that may alter their operation.
These factors, for example, comprise:
plugging of the probe orifices by dust or insects,
lightning strikes,
avian impacts during flight,
mechanical impacts occurring on the ground, and/or
icing.
As shown by the databases inventorying aeronautic incidents, these factors are a source of failures for protruding probes. These failures can result in erroneous measurements.
In order to offset these problems, the aeronautic certification rules require having redundant primary reference measurement capabilities on the aircraft.
The commonly used solutions consist of having back-up probes, or combining a redundant probe with a pre-existing probe.
Furthermore, multifunctional probes exist for example combining static and total pressure probes with a temperature probe.
However, these solutions are not fully satisfactory.
In fact, most of the existing redundant probes are of the protruding type, and consequently have failure risks of the same nature as the probes that they are intended to back up.
A primary reference probe of the aforementioned type is described in FR 2,994,273. However, such a probe does not in itself allow the determination of all of the primary references, and an anemo-barometric measuring system comprising such a probe needs data other than that measured by the probe, or by a second probe of the same type, to determine the set of primary references.
Lastly, the combination of a probe with a pre-existing probe may require a new certification of the resulting probe if its geometry is altered.